Dating found in bolivia sites
The geologist may have found some fossils in Sedimentary Rocks A and discovered that they are similar to fossils found in some other rocks in the region.He assumes therefore that Sedimentary Rocks A are the same age as the other rocks in the region, which have already been dated by other geologists.No matter what the radiometric date turned out to be, our geologist would always be able to ‘interpret’ it.He would simply change his assumptions about the history of the rock to explain the result in a plausible way. Wasserburg, who received the 1986 Crafoord Prize in Geosciences, said, ‘There are no bad chronometers, only bad interpretations of them!
Or he may suggest that the result was due to a characteristic of the lava—that the dyke had inherited an old ‘age’. 200.4 ± 3.2 million years) implies that the calculated date of 200.4 million years is accurate to plus or minus 3.2 million years.
Clearly, Sedimentary Rocks A were deposited and deformed before the Volcanic Dyke intruded them.
These were then eroded and Sedimentary Rocks B were deposited.
From his research, our evolutionary geologist may have discovered that other geologists believe that Sedimentary Rocks A are 200 million years old and Sedimentary Rocks B are 30 million years old.
Thus, he already ‘knows’ that the igneous dyke must be younger than 200 million years and older than 30 million years.
It is clear that the sedimentary rock was deposited and folded before the dyke was squeezed into place.